AND 和 OR 与 NSPredicate 结合。 IOS 斯威夫特

Question

我的核心数据 get 查询的动态 or 谓词

    var predicate = [NSPredicate]()
    //this three is or
        predicate.append(NSPredicate(format: "item_parent_id = %i", 1))
        predicate.append(NSPredicate(format: "item_parent_id = %i", 3))       
        predicate.append(NSPredicate(format: "item_parent_id = %i", 5))

    // but this one is and
        predicate.append(NSPredicate(format: "price_date CONTAINS[cd] %@", 'timestamp'))

    var compound = NSCompoundPredicate.orPredicateWithSubpredicates(predicate)

前三个约束用于 OR 运算符，最后一个约束用于日期与

我为此花了很多时间，我是 swift 开发的新手，我不习惯 Objective C，这就是为什么我很难将我在 Objective C 中发现的内容翻译成 swift。

如果可能的话 swift 写下答案，任何评论和建议都会有很大帮助。先谢谢了

obj c - source #1
obj c - source #2

Answer 1

如果你正在寻找像(a OR b OR c) AND d 这样的操作，你需要两个复合谓词：

var orList = [NSPredicate]()
//this three is or
orList.append(NSPredicate(format: "item_parent_id = %i", 1))
orList.append(NSPredicate(format: "item_parent_id = %i", 3))       
orList.append(NSPredicate(format: "item_parent_id = %i", 5))
let orPredicate = NSCompoundPredicate.orPredicateWithSubpredicates(orList)

// but this one is and
let other = NSPredicate(format: "price_date CONTAINS[cd] %@", 'timestamp')

let compound = NSCompoundPredicate.andPredicateWithSubpredicates([orPredicate, other])